Method and apparatus in a communication receiver for estimating symbol timing and carrier frequency
First Claim
1. A method in a communication receiver for estimating a symbol timing and a carrier frequency of a received data signal, the method comprising the steps of:
- receiving at least one modulated signal;
demodulating the at least one modulated signal to recover a timing signal and a data signal comprising a plurality of data symbols;
determining a rough symbol timing from the timing signal;
forming a timing-carrier search matrix comprising the step ofcomputing from the plurality of data symbols a plurality of signal quality metrics as a function of a plurality of predetermined trial variations of the carrier frequency about a nominal carrier frequency and as a function of a plurality of predetermined trial variations of the symbol timing about the rough symbol timing; and
making an estimate of the symbol timing and an estimate of the carrier frequency by locating a minimum one of the plurality of signal quality metrics in the timing-carrier search matrix.
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Accused Products
Abstract
A communication receiver (300) receives (404) a modulated signal, and demodulates the modulated signal to recover a timing signal (202) and a data signal (204) including data symbols. A processing system (316) of the communication receiver determines (406) a rough symbol timing from the timing signal, and forms (408) a timing-carrier search matrix by computing signal quality metrics from the data symbols as a function of predetermined trial variations of the carrier frequency about a nominal carrier frequency and as a function of predetermined trial variations of the symbol timing about the rough symbol timing. The processing system then estimates (410) the symbol timing and the carrier frequency by locating a minimum one of the plurality of signal quality metrics in the timing-carrier search matrix.
18 Citations
18 Claims
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1. A method in a communication receiver for estimating a symbol timing and a carrier frequency of a received data signal, the method comprising the steps of:
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receiving at least one modulated signal; demodulating the at least one modulated signal to recover a timing signal and a data signal comprising a plurality of data symbols; determining a rough symbol timing from the timing signal; forming a timing-carrier search matrix comprising the step of computing from the plurality of data symbols a plurality of signal quality metrics as a function of a plurality of predetermined trial variations of the carrier frequency about a nominal carrier frequency and as a function of a plurality of predetermined trial variations of the symbol timing about the rough symbol timing; and making an estimate of the symbol timing and an estimate of the carrier frequency by locating a minimum one of the plurality of signal quality metrics in the timing-carrier search matrix. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A communication receiver for estimating a symbol timing and a carrier frequency of a received data signal, the communication receiver comprising:
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a receiver element for receiving at least one modulated signal, the receiver element comprising a demodulator for demodulating the at least one modulated signal to recover a timing signal and a data signal comprising a plurality of data symbols; and a processing system coupled to the receiver element for determining a rough symbol timing from the timing signal, wherein the processing system is programmed to; form a timing-carrier search matrix by computing from the plurality of data symbols a plurality of signal quality metrics as a function of a plurality of predetermined trial variations of the carrier frequency about a nominal carrier frequency and as a function of a plurality of predetermined trial variations of the symbol timing about the rough symbol timing, and make an estimate of the symbol timing and an estimate of the carrier frequency by locating a minimum one of the plurality of signal quality metrics in the timing-carrier search matrix. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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Specification